Waste polystyrene, such as expanded polystyrene, presents particular economic and environmental problems. The density of expanded polystyrene is such that carrying waste expanded polystyrene on trucks is very wasteful. More specifically, expanded polystyrene has such a low density, and hence high relative volume per unit mass, that trucks used to transport waste expanded polystyrene often “bulk out”. In other words, trucks, semi-trucks, tractor-trailers, large rigs, 18-wheeler rigs, etc., can each be filled with expanded polystyrene without any reaching their load carry capacity.
In addition, the environmental impact of waste expanded polystyrene is a serious matter. Waste expanded polystyrene takes up a disproportionate amount of space at landfill sites. Recycling expanded polystyrene is economically wasteful in light of the “top out” problem.
There are several issued U.S. Patents devoted to dealing with the economic and environmental issues surrounding the burying or recycling of waste expanded polystyrene, such as U.S. Pat. No. 6,169,121, issued Jan. 2, 2001 to Noguchi et al. The '121 patent describes a processing method for effectively and promptly removing insoluble components contained in a solution of a styrene resin waste material to enable regeneration of high-quality regenerated styrene. A solution of the styrene resin waste material in an organic solvent is processed with, for example, a dehydrating agent, to remove insoluble components. The resulting clarified solution is degasified on heating in vacuum to remove the organic solvent for recycling the resulting mass as a regenerated styrene resin.
U.S. Pat. No. 6,098,649, issued Aug. 8, 2000 to Aug. 8, 2000, describes a waste recovery system using this apparatus and a liquid container ideal for use with the waste processing apparatus and waste recovery system. The waste processing apparatus comprises a processing part for processing supplied waste (for example foam polystyrene) with a processing liquid (for example limonene) and a storing part for storing produced liquid (for example limonene containing dissolved foam polystyrene) produced in this processing part and provided with a removable liquid container constructed to both supply processing liquid to the processing part and receive produced liquid produced by the waste processing apparatus. In the waste recovery system, the liquid container is removed from the waste processing apparatus after receiving the produced liquid and carried to a waste recycling apparatus, the produced liquid is transferred from the liquid container into the waste recycling apparatus, waste or waste and processing liquid is recovered from the produced liquid by the waste recycling apparatus and the empty liquid container is filled with new or recycled processing liquid and returned to the waste processing apparatus again.